Developments in hepatitis C during 1997-1999

Hepatitis C has become an area of intensive research over the past several years. With current worldwide prevalence estimated at 150 to 200 million people, and with almost four million Americans infected, it is a major public health issue. Of those infected, over 85% will develop chronic infection. Of those who develop chronic infection, 20% will develop cirrhosis, and in the cirrhotic population, 20% develop hepatocellular carcinoma. It is still difficult in the early stages of disease to determine who is at risk of developing cirrhosis, and therefore who would benefit most from therapy. However, even in the non-cirrhotic individual, there are many symptomatic manifestations of the disease that lead clinicians to initiate therapy. The ultimate goal of treatment is to achieve sustained eradication of the virus. Until recently, the mainstay of treatment has been interferon (IFN-) monotherapy, which is less than 25% effective and is generally accompanied by side effects. Newer therapeutic modalities focus on less toxic compounds, targeting viral proteins such as protease or helicase, or viral genomic segments with antisense peptides and ribozymes. This chapter is an overview of the patent literature from 1997 to mid-1999 and discusses possible new treatment options including vaccines and delivery systems to cells.